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From James Taylor <jamestay...@apache.org>
Subject Re: hotspot in System.catalog table
Date Fri, 13 Apr 2018 05:43:44 GMT
Try setting the UPDATE_CACHE_FREQUENCY table property (and configuring
the phoenix.default.update.cache.frequency system-wide property). That'll
prevent pinging the region hosting SYSTEM.CATALOG every time a query is
compiled. We've found value of even 5 seconds makes a big difference. For
more on that, see here[1] and here[2].

In the future, we'll let the SYSTEM.CATALOG table span multiple regions -
keep an eye on PHOENIX-3534.

Thanks,
James

[1] https://phoenix.apache.org/#Altering
[2] https://phoenix.apache.org/language/index.html#options

On Thu, Apr 12, 2018 at 10:32 PM, anil gupta <anilgupta84@gmail.com> wrote:

> Hi All,
>
> System.catalog table seems to be single region table(correct?). We are
> currently facing a problem of hotspot on System.catalog table.
> One of our app does around 4-5k select queries/sec. And, It is creating a
> new preparedstatement everytime. I suspect that while instantiating a new
> preparedstatement(contrary to Statement), system.catalog table is queried
> first. Hence, it is resulting into hotspotting. Is my analysis correct?
>
> (I have already suggested my colleagues to try using Statement instead of
> PS if they have to create a new one everytime.)
>
> --
> Thanks & Regards,
> Anil Gupta
>

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